Radiotelephones permit a user to communicate over a wireless system at virtually any location. The radiotelephone communicates with a receiving station using a low voltage, radio frequency signal. At the receiving station, connections are provided to conventional telephone systems. Radiotelephones may be part of cellular telephone systems, cordless telephone systems, such as second generation cordless telephone (CT2) or other wireless telephone systems.
Radiotelephone handsets have been produced in a variety of designs. The goal of these designs is generally to reduce the physical size of the handset while retaining full functionality as well as ease of use and convenience for the user.
One type of radiotelephone handset is a foldable radiotelephone. A foldable radiotelephone generally includes two housing elements connected by a hinging mechanism. When the radiotelephone is not in use, the two housing elements may be folded to a smaller, more compact configuration while rotating the hinging mechanism.. When the radiotelephone is in use, the two housing elements may be unfolded. The two housing elements are generally called a body housing and a flap housing.
Some foldable radiotelephone handsets include a switch for activating the radiotelephone when handset is unfolded. In response to activation of the switch, the radiotelephone is placed in an off hook condition, or otherwise made ready to initiate a call. When the handset is folded, the switch is deactivated, placing the radiotelephone in a standby or on hook condition for receiving a call.
Previous handsets have used proximity detection devices, such as a reed switch and magnet, to provide the switch which activates the radiotelephone. When the handset is folded and unfolded, moving the two housing elements into and out of proximity, this motion is detected by the switch.
Such proximity detectors are relatively expensive, and add to the total parts count and manufacturing costs of the handset. Since radiotelephones are consumer devices, sales and marketing of radiotelephones are extremely sensitive to costs. Also, the relatively high parts count increases manufacturing costs as the many parts must be assembled.
Other foldable radiotelephone handsets have provided a switch having an on-off actuator which protrudes through an opening in one of the handset housing elements. As the handset is folded, the actuator is engaged by a portion of the other housing element, thereby actuating the switch.
Use of this type of switch has been limited by the need to provide an opening in the one housing element for the actuator. Such an opening admits dirt, moisture and other contaminants into the housing. Such contaminants can adversely affect the operability of the radiotelephone.
Generally, in foldable radiotelephone handsets, one housing element includes an earpiece and the housing element includes a microphone. A user holds the unfolded phone adjacent to the user's head with the earpiece proximate user's ear and the microphone proximate the user's mouth. For good acoustical performance, the flap housing must be held in an optimal position relative to the body housing of the handset. This optimal, open position generally orients the flap housing at an angle relative to the body housing.
Previous radiotelephone handsets have included a detent mechanism to maintain the flap housing in the predetermined open position. As the handset is unfolded, the detent mechanism snaps or clicks into place to locate or lock the flap housing in the predetermined open position. A small amount of pressure on the flap housing causes the detent mechanism to unlock, so the handset can be folded.
Such previous detent mechanisms have required many individual parts to implement. These parts must be assembled with the flap housing, a procedure which can be difficult and time-consuming because of the small size of some of the parts. High part count and difficulty of assembly add to the manufacturing costs of the completed radiotelephone. Accordingly, a flap housing providing a detent mechanism and a switch actuator is required to reduce manufacturing costs, as well as the finished product cost associated with a radiotelephone.